Ok, you will need to fill in the measure for light intensity since i don't know how to translate it.
At 500 (something)- photosynthesis becomes obvious because the rate of oxygen production excedes that of oxygen consumption by respiration
At 50.000 - photosynthesis is maximum.
Between 50.000-100.000- photosynthesis is not influenced. This means, that if you increase the intensity from 50.000 to 100.000 it will not matter
Over 100.000 - the rate of photosynthesis drops, light causes cellular lesions

"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter